Developing Allergies

Myth: Allergies can only develop in children.
Fact: While many allergies tend to present during childhood, it is not uncommon to develop allergies as an adult. In fact, no individual is born with allergies. Allergies can develop at any time and can affect individuals of all ages. Approximately 30-90 million individuals in the U.S. are affected by hay fever, with 20% of those developing symptoms after the age of 20. Interestingly, even if symptoms such as sneezing, itchy eyes and runny nose started in childhood, they often peak in early adulthood in the third or fourth decade of life. 

Another common allergy that develops in adulthood can be to medications. Allergies are acquired through exposure to medications, such as antibiotics, which occur over a person’s lifetime. Even if an individual was originally able to tolerate the medication, a new allergy can develop with subsequent exposures later in life. The most common age of developing a new medication allergy is between 20-49 years of age, but as patients get older, medication allergies should always be evaluated by a board-certified allergist / immunologist as patients often lose these allergies with time. 

Genetics certainly plays a role in determining whether a person is likely to develop allergies. For example, if a parent has allergies, the child has an increased risk of developing allergies but not necessarily to the exact same pollen or medication. 

However, other factors such as stress, infection and changes in the environment can alter an individual’s immune system over time and increase their risk of developing allergies later in life. 

Find out about more myths in allergic diseases.

Find out more about hay fever / rhinitis.

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10/2/2025